Rotary plug valve



March 1949. w. T. DOWNING EI'AL 2,464,123

ROTARY PLUG VALVE Filed June 11, 1946 6 2 40 I 42 2 v w INVENTORS WILLIS r. oownme SIDNEY e JOHNSON FIG.2 I 'MLZ,

Patented Mar. 8, 1949 ROTARY PLUG VALVE Willis T. Downing, Alexandria, Va., and Sidney P. Johnson, Washington, D. 0.

Application June 11, 1946, Serial No. 676,046

2 Claims. (Cl. 251-437) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) This invention relates to a rotary plug valve which is axially movable; and in particular to a rotary plug valve which does not rotate with respect to the valve seat when in seated position.

Axially movable rotary plug valves are known in the art in which the plug is adapted to be lifted from its seating contact before rotationto open position. These valves are generally pro vided with two operating hand wheels which separately function to lift the plug and to rotate it. Or they may be of other design involving a complicated system of levers, guides and spring-actuated stops which make the valve defective in operation. In most cases present art valves of this type operate in the open position with the rotary plug in unseated position. This is a defect which permits the fluid being controlled to pass around the plug and in some cases to be in contact with the packing in the valve stem packinggland. Such construction has a deleterious effect on the valve seat and also the packing and valve stem.

With these defects in view it is, therefore, an object of this invention to provide an improved valve of the rotary axially movable plug type which is adapted to be lifted from contact with its seat before either opening or closing the valve.

It is also an object of this invention to provide a valve of the rotary axially movable plug type which cannot be rotated when the plug is in corn tact with its valve seat.

it is a further object of this invention to provide a valve of the rotary, axially movable plug type which is adapted to be operated by a single hand wheel.

it is an additional object of this invention to provide a valve of the rotary, axially movable plug type, which by reason of the fact that the plug is seated when in either open or closed 320- sltion, is adapted for service in salt water, gasoline or high pressure steam lines, and

It is a still further object of this invention to provide a valveof the rotary, axially movable plug type which is of simple, sturdy construction and capable of economical manufacture.

In order that a clear conception may be had of the construction by which these objectives are attained, reference is now made to the drawings which are illustrative of a preferred embodiment Figure 2 is a partial sectional view taken on line 2-2 of Figure 1 looking in the direction indicated by the arrows. It shows the relationship of the rotation limiting and indexing cam to the spring actuated pawl.

In the drawings It represents a valve body which is provided with passageway l2 extending therethrough for the conduction of fluid. Body id is provided with a frustro-conically shaped cavity M which is positioned centrally of the body on the median axis at right angles to the center line of passage l2. Cavity I4 is provided with valve seats l6 and I8. The bottom of valve body it is provided with a countersunk pin 23 which is centered on the above median axis and projects into cavity 84. The interior face of the bottom of body It is provided with transverse ribs 22 which are positioned at right angles to each other and with one rib parallel with passageway i2. Valve body E0 is provided with conventional flanges 24 and 26 which are adapted to be connected to pipe lines in the usual manner. Body ill is also provided with flange 28 which is adapted to support yoke 30. Rotary plug 32 is frustroconical in shape. It is adapted to fit within cavity l4 and is provided with seats 32 and 35 to contact valve seats to and i8 respectively. Plug 32 is provided with a transverse passage way 36 which matches with passageway l2 when in open seated position. Plug 32 is provided with transverse slots 38 and. an opening Eli in its bottom which are adapted to interflt with transverse ribs 22 and pin 20 respectively. Valve stem 2d extends from the larger end of plug 32 through packing gland 52 which is adapted to engage boss at in the'base' of yoke Stem Qt is of uniform diameter to shoulder ill where its diameter is reduced and is provided with right hand threads as at Alt which are adapted to match threads 50 in bushing 52. The end of stem to is provided with a slot ll which is positioned in parallel with passageway 36. This slot thus readily indicates the position of passageway 36.

Bushing 52 is journaled in the arms of yoke 38 as at M and. is free to rotate with respect thereto. Bushing 52 extends through the'hub of handwheel 58 and is firmly attached thereto by means of locknut 58 which threadedly engages the extension of bushing 52 and clamps the hub of handwheel 56 between a shoulder on the bushing and itself. The large portion of stem 50 is provided with a four tooth indexing cam 68 which is adapted to engage spring biased pawl 62 which is mounted in an arm of yoke 30. These teeth are indexed with the letter O or S to indicate the "open" or "shut position of the valve. when a tooth of the cam is engaged by pawl i2 rotation of the stem and valve plug in a counterclockwise direction is prevented.

In operation the valve is manipulated as follows: Assuming the valve to be closed and in seated position, hand-wheel "is rotated in a clockwise direction. Plug 32 and stem 40 are prevented from rotation by transverse ribs 22 in the bottom of valve body ID with which the plug is engaged. Bushing 52 rotates with handwheel 56 and since its threads which engage stem 40 are right-handed, clockwise rotation of the hand-wheel lifts or jacks" the valve plug from its seat. At the time at which the valve plug clears ribs 22, shoulder 46 on valve stem 40 Jams on the under surface of bushing 52 and valve plug 32 and hand-wheel 56 then rotate as a unit.

Hand-wheel 56 is then rotated through an angle of 90 or until pawl 62 drops over the edge of the tooth marked 0" on cam 60. At this point passageway 36 is in alignment with passageway i2. Valve plug 32 is then seated by rotating hand-wheel 56 in a counterclockwise direction until ribs 22 engage slots 38 and theseats on the plug and valve body are in contact with each other. To close the valve the above operations are repeated. First the plug is jacked from its seat by a clockwise rotation of the hand-wheel. The valve is then rotated in a clockwise direction until pawl 52 drops over the tooth on cam 50 marked S and the hand wheel is then rotated in counter-clockwise direction until the plug is seated.

It is apparent that these inventors have provided a rotary plug valve which never rotates when in seated position, a fact which prevents rapid erosion of the valve seats. Also by reason of the fact that the rotary plug is seated when in open and closed positions the valve can be used in high pressure steam service, on salt water lines, on gasoline lines, l. e. on high duty service.

While the preferred embodiment of the invention is that shown by the drawings, it is not desired to be strictly limited thereto as modifications in the various parts and their relative locations can be made without departing from the spirit or scope of the invention as defined by the herewith appended claims.

The invention described herein may be manufactured and used by or for the Government of lfgianially movable plug type comprising a valve body ."having apassageway extending therethrough. :a rotary plug adapted to be seated and unseat'ed'in the valve a body when moved axiallyra valve seatlextend-h ing transversely of the body, said valve seat being or greater length than the lplug to allow axial movement of the plug, sald-plugin its seated position being in contact with the seat, said plug having a transverse passageway adapted to align with the passageway through said body, a frame mounted on said valve body, actuating means in-- cluding a bushing rotatably mounted in said 1 frame, a valve stem extending fromsaid plug and having a threaded connection with said bushing so that rotation .of said bushing relative to said stem effects axial movement of said stem to seat and unseat said plug, means carried by said stem and engageable with said bushing for coupling said stem and bushing for rotation together when said plug is unseated so that rotation of said bushing efiects rotation of said plug, and means carried by said frame for opposing rotary movement of said stem in a direction opposite to the direction of rotation of said bushing to.rotate the plug whereby when said bushing is rotated in the said opposite direction the plug is moved axially to reseated position.

2. A valve as called for in claim 1 having means for preventing rotation of the plug when the latter is in seated position and substantially until said bushing engageable means carried by the stem is in engagement with the bushing.

WILLIS T. DOWNING. SIDNEY P. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Foster Apr. 15, 1941 "erica ior' governmental 

